October 2007

Documenting skills is value-add

ISA certification provides an objective, third-party assessment, and confirmation of a person's skills. It gives manufacturing and factory staff the opportunity to differentiate themselves from their peers and gain recognition. InTech covers three certification areas in its monthly Certification department.

ISA Certified Automation Professional (CAP) program

Certified Automation Professionals (CAPs) are responsible for the direction, design, and deployment of systems and equipment for manufacturing and control systems.

The following questions come from the CAP study guide, Performance Domain III, System Design: Design, specify, and procure the hardware/software used in the system.

CAP questions

1. If you need an enclosure that resists corrosion and provides protection for outdoor use, dust, and hose-directed water, which type of enclosure would you select?

 A. Type 1 (NEMA 1)
 B. Type 4x (NEMA 4x)
 C. Type 12 (NEMA 12)
 D. Type 13 (NEMA 13) 

2. According to the NFPA 79, the standard wire colors for line voltage, AC control currents, DC control circuits, and interlock circuits are respectively shown as:

 A. Black, red, blue, yellow
 B. Black, red, orange, yellow
 C. Brown, red, orange, yellow
 D. Brown, black, white, red 

CAP answers

1. The correct answer is B, Type 4x (NEMA 4x).

NEC (National Electrical Code) 2002 defines an enclosure Type 4x as ideal for outdoor use and resistant to splashing water, windblown dust, hose directed water, and corrosion. It is also undamaged by the formation of ice on the enclosure. 

A Type 1 enclosure is for indoor use. 

A Type 12 enclosure is for indoor use and resists only dust and dripping non-corrosive liquids. 

A Type 13 enclosure is for indoor use and resists dust, spraying water, oil, and non-corrosive coolants.

Reference: Mark W. Earley, Editor; NEC 2002 Handbook; NFPA, 2002 

2. The correct answer is A, black, red, blue, and yellow.      

Black, red, blue, yellow is the correct answer per NFPA-79: The Electrical Standard for Industrial Machinery, which is in correspondence with article 670 in the National Electrical Code (NEC). This is located in section 14.2: Identification of Conduction.

NFPA is the National Fire Protection Association (established 1896) an independent, voluntary-membership, non-profit (tax-exempt) organization. 

Incorporated in 1930 in Massachusetts, NFPA's mission is to reduce the worldwide burden of fire and other hazards on the quality of life by providing and advocating scientifically-based consensus codes and standards, research, training, and education. 

NFPA's international headquarters is in Quincy, Mass.
Reference: NFPA-79; Electrical Standard for Industrial Machinery, NFPA, 2002

ISA Certified Control Systems Technician (CCST) program

Certified Control System Technicians (CCSTs) calibrate, document, troubleshoot, and repair/replace instrumentation for systems that measure and control level, temperature, pressure, flow, and other process variables.

This question comes from the Level I study guide, Domain 3, Troubleshooting. Level I represents a professional who has a five-year total of education, training, and/or experience.  

CCST question

Control valves, which have a plug positioned by a stem, which slides through a packing gland, are often referred to as:

A. Rotary motion control valves
B. Linear stem motion control valves
C. Ball-control valves
D. Motorized control valves 

This globe valve is one kind of linear stem motion control valve.

CCST answer

A rotary valve has a flow closure member that rotates in the flow stream to modify the amount of fluid passing through the valve.

A linear valve or a globe valve refers to the linear or straight-line movement of the plug and stem. Some valves use a movable part like a ball, a disk, a gate, in the flow path to modify the rate of flow through the valve.

The best answer to this question is B.

ISA Certified Industrial Maintenance Mechanic (CIMM) program

Certified Industrial Maintenance Mechanics (CIMMs) are responsible for preventive, predictive, and corrective maintenance. They are multi-skilled individuals whose expertise is primarily mechanical in nature as opposed to instrumentation or electrical.

CIMMs have a minimum of five years of relevant work experience in the maintenance mechanic field or three years experience and a two-year associate degree in maintenance or a related field. This question is from Performance Domain III: Troubleshooting and Analysis.

CIMM question

In a portable water pump the MOST common type of material used for a primary ring in a standard pump seal is:

A. Carbon
B. Tungsten carbide
C. Stainless steel
D. Carbon steel 

CIMM answer 

The correct answer is A, carbon.

A seal is a device designed to prevent the movement of fluid from one area to another, or to exclude contaminants. 

The type of chemicals used in a process dictate of what material the mating rings of a seal are made. Carbon displays excellent lubricating properties and does not react to most types of materials and chemicals.

Nicholas Sheble (nsheble@isa.org) writes and edits the Certification department.